Low Anti-Factor Xa Level Predicts 90-Day Symptomatic Venous Thromboembolism in Surgical Patients Receiving Enoxaparin Prophylaxis: A Pooled Analysis of Eight Clinical Trials

Autor: John R. Stringham, Lyen C. Huang, Arash Momeni, Christopher J. Pannucci, Thomas K. Varghese, Kory I. Fleming, Corinne Bertolaccini, T Bartley Pickron, Ann Marie Prazak
Rok vydání: 2023
Předmět:
Zdroj: Ann Surg
ISSN: 1528-1140
Popis: Objective To examine the relationship between enoxaparin dose adequacy, quantified with anti-Factor Xa (aFXa) levels, and 90-day symptomatic venous thromboembolism (VTE) and post-operative bleeding. Summary background data Surgical patients often develop "breakthrough" VTE events-those which occur despite receiving chemical anticoagulation. We hypothesize that surgical patients with low aFXa levels will be more likely to develop 90-day VTE, and those with high aFXa will be more likely to bleed. Methods Pooled analysis of eight clinical trials (N = 985) from a single institution over a four year period. Patients had peak steady state aFXa levels in response to a known initial enoxaparin dose, and were followed for 90 days. Survival analysis log-rank test examined associations between aFXa level category and 90-day symptomatic VTE & bleeding. Results Among 985 patients, 2.3% (n = 23) had symptomatic 90-day VTE, 4.2% (n = 41) had 90-day clinically relevant bleeding, and 2.1% (n = 21) had major bleeding. Patients with initial low aFXa were significantly more likely to have 90-day VTE than patients with adequate or high aFXa (4.2% vs. 1.3%, p = 0.007). In a stratified analysis, this relationship was significant for patients who received twice daily (6.2% vs. 1.5%, p = 0.003), but not once daily (3.0% vs. 0.7%, p = 0.10) enoxaparin. No association was seen between high aFXa and 90-day clinically relevant bleeding (4.8% vs. 2.9%, p = 0.34) or major bleeding (3.6% vs. 1.6%, p = 0.18). Conclusions This manuscript establishes inadequate enoxaparin dosing as a plausible mechanism for breakthrough VTE in surgical patients, and identifies anticoagulant dose adequacy as a novel target for process improvement measures.
Databáze: OpenAIRE